This invention relates to an improved engine unit for a motor vehicle and more particularly to an improved compact engine drive arrangement for such vehicles.
As is well known, the spatial requirements of motor vehicles are becoming quite critical. This is due to the increased complexity of the engines, transmissions and the number of accessories driven by the engine. Also, the configuration of modern motor vehicles and their streamlining dictates relatively small and sometimes undesirable configurations for the engine compartment in order to achieve the overall design effects of the vehicle. In order to achieve low hood lines and better streamlining, resort has been made to positioning the engine transversely in the engine compartment in a front engine, front wheel drive vehicle. Of course, such transverse engine locations in rear engine, rear wheel drive vehicles are also widely used. However, even though such an orientation can improve the layout of the engine compartment, there still is a problem in connection with the shape of the hood line. Specifically, if the engine cylinders are erect or forwardly inclined, they intrude into the forward portion of the hood area and dictate a high height in this region. This is unacceptable from both streamlining and aesthetic reason.
In addition to the orientation of the cylinders of the engine, the transverse postioning of the engine in the engine compartment also makes it extremely important to insure that the length of the engine (the portion extending transversely across the engine compartment) is short. As is well known, the power output of an engine and its efficiency can be increased if one or more overhead mounted camshafts are employed for operating the valve train. Conventionally such camshafts are driven off one end of the crankshaft and this obviously increases the length of the engine and gives rise difficulties to in placement of the engine transversely in the engine compartment.
It is, therefore, a principal object of this invention to provide an improved camshaft drive arrangement for an internal combustion engine.
It is a further object of this invention to provide an improved and compact camshaft drive arrangement for an internal combustion engine in which the length of the engine is not increased so as to permit the engine to be used in a transverse position in an engine compartment of a motor vehicle.